December 17 Events By JusticeS97 Dec 17, 942 Assassination of William I Longsword, 2nd Duke of Normandy. Dec 17, 1790 Aztec calendar stone discovered in Mexico City Dec 17, 1923 Greek king George II overthrown by army/republic Dec 17, 1925 Soviet Union & Turkey sign non-aggresion pact Dec 17, 1941 World War II: Beginning of the Siege of Sebastopol. Dec 17, 1944 US Army announces end of excluding Japanese-Americans from West Coast, detainees released. Dec 17, 1971 Cease fire between India & Pakistan in Kashmir Dec 17, 1977 Elvis Costello & The Attractions 1st US TV appearance (SNL) Dec 17, 1991 NBA's most lopsided game Cleveland beats Miami 148-80 Dec 17, 2012 NASA completes a successful mission to map the Moon’s gravity field